1. DRUGS FOR COUGH
Dr.Vijay Bhushanam

2. Cough (Introduction)
• Cough is an explosive expiration, that provides a normal
protective mechanism for clearing the tracheo-bronchial
tree of secretions and foreign material.
• When excessive or bothersome, it is also one of the most
common symptoms for which patients seek medical
attention.
• Reasons for this include discomfort from the cough itself,
interference with normal lifestyle, and concern for the
cause of the cough, especially fear of cancer.

3. Mechanism of cough
• Coughing may be initiated either voluntarily or reflexively.
• As a defensive reflex it has both afferent and efferent
pathways.
• The afferent limb includes receptors within the sensory
distribution of the trigeminal, glossopharyngeal, superior
laryngeal and vagus nerves.
• The efferent limb includes the recurrent laryngeal nerve
and the spinal nerves.

4. Mechanism of cough (Cont.)
• Deep inspiration glottic closure  relaxation of the
diaphragm  muscle contraction against a closed glottis
 markedly positive intrathoracic pressure narrowing
of the trachea  glottis opens at once  the large
pressure differential between the airways and the
atmosphere coupled with tracheal narrowing produces
rapid flow rates through the trachea COUGH
• The shearing forces that develop aid in the elimination of
mucus and foreign materials.

5. Etiology of Cough
• The most common causes of cough can be categorized
according to the duration of the cough.
• Acute cough (<3 weeks): URTIs (especially the common
cold, acute bacterial sinusitis, and pertussis), pneumonia,
pulmonary embolus, and congestive heart failure.
• Sub-acute cough (3-8 weeks): post-infectious
• Chronic cough (>8 weeks):
In a smoker: chronic obstructive lung disease or
bronchogenic carcinoma.
In a nonsmoker: postnasal drip (sometimes
termed the upper airway cough syndrome), asthma, and
gastroesophageal reflux.

6. Types of Cough
• Non-productive (dry): No useful purpose, increases
discomfort to the patient  needs suppression
• Productive (tenacious): Presence of excessive
sputum  suppression not desired  needs
coughing/clearing out of the sputum

7. Classification of drugs for Cough
•
•
•
•
Pharyngeal demulcents: Lozenges, cough drops, linctuses
containing syrup, Glycerine, Liquorice
Expectorants:
1. Mucokinetics (Bronchial secretion enhancers): Sodium or
potassium citrate, Potassium iodide, Guaphenisin (Glyeryl
guaiacolate), balsum of Tolu, Vasaka, Ammonium chloride.
2. Mucolytics: Bromhexene, Ambroxol, Acetylcystein,
Carbocystein
Antitussives (Cough center supressants):
a) Opioids: Codein, Pholcodein
b) Non-opioids: Noscapine, Dextromethorphan, Chlophedianol
c) Antihistaminics:Chlorpheniramine, Diphenhydramine,
Promethazine
Adjuvant antitussives:
Bronchodilators: Salbutamol, Terbutaline

8. Pharyngeal demulcents
• Sooth the throat and reduce afferent impulses from the
inflamed/irritated pharyngeal mucosa.
• E.g: Lozenges, cough drops, linctuses containing syrup,
Glycerine, Liquorice

9. Expectorants
• Increase bronchial secretions or reduce its viscosity,
facilitating its removal by coughing
• E.g:
• Mucokinetics (Bronchial secretion enhancers): Sodium or
potassium citrate, Potassium iodide, Guaphenisin (Glyeryl
guaiacolate), balsum of Tolu, Vasaka, Ammonium
chloride.
• Mucolytics: Bromhexene, Ambroxol, Acetylcystein,
Carbocystein

10. Antitussives
(Cough center supressants)
• These act
– in CNS to raise the threshold of cough center (and/or)
– peripherally in Respiratory tract to reduce tussal impulse
• Should be used only for dry unproductive cough (or)
• if the cough is unduly tiring, disturbs sleep (or)
• is hazardous (hernia, piles, cardiac ds., ocular surgery etc)
• E.g:
• Opioids: Codein, Pholcodein
• Non-opioids: Noscapine, Dextromethorphan,
Chlophedianol
• Antihistaminics: Chlorpheniramine, Diphenhydramine,
Promethazine

11. Bronchodilators
• Bronchospasm can induce/aggravate cough, especially
in individuals with bronchial hyperreactivity
• Bronchodilators relieve cough in such individuals
• Improve the effectiveness of cough in clearing
secretions by increasing the surface velocity of airflow
during cough
• E.g: Salbutamol, Terbutalin

12. Antitussive/Expectorant
Combinations
• AMBRODYL PLUS: Ambroxol, Chlorpheniramine,
Salbutamol, Guaphenesin.
• ASTHALIN: Salbutamol, Guaphenesin.
• ASCORIL-C: Codeine, Chlorpheniramine.
• BENADRYL: Diphenhydramine, Ammonium chloride,
Sodium citrate, Menthol.
• GRILINCTUS: Dextromethorphan, Chlorpheniramine,
Guaphenesin, ammonium chloride.

13. Specific Rx for cough
• URTI/LRTI  Appropriate antibiotics
• Smoking/Chr. Bronchitis  Cessation of smoking/
avoidance of pollutants
• PTB ATT
• Post nasal drip due to sinusitis Antibiotics/Nasal
decongestants/H1 antihistaminics
• Postnasal drip due to allergy Avoidance of precipitating
factors/Corticosteroid nasal spray/H1 antihistaminics
• GERD H2 blockers/PPIs/Cisapride
• ACE inhibitor induced cough  Switch to ARBs/CCBs
• Asthmatic cough Inhaled β2
agonists/Ipratropium/Corticosteroids

14. THANK
YOU